diff --git a/go/pserver/client/client_test.go b/go/pserver/client/client_test.go
index 21dac92417fe1276c761bdf9d0ace523293a1004..27f4ff2380b3b5aa01485838eb4a876a8863d901 100644
--- a/go/pserver/client/client_test.go
+++ b/go/pserver/client/client_test.go
@@ -3,11 +3,13 @@ package client_test
 import (
 	"context"
 	"io/ioutil"
+	"math/rand"
 	"net"
 	"net/http"
 	"net/rpc"
 	"strconv"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -111,16 +113,23 @@ func testClient(t *testing.T, c *client.Client) {
 	if err != nil {
 		t.Fatalf("read optimizer proto failed")
 	}
+
+	var wg sync.WaitGroup
 	for i := 0; i < numParameter; i++ {
-		var p pserver.Parameter
-		p.Name = "p_" + strconv.Itoa(i)
-		p.ElementType = pserver.Float32
-		p.Content = make([]byte, (i+1)*100)
-		err := c.InitParam(pserver.ParameterWithConfig{Param: p, Config: config})
-		if err != nil {
-			t.Fatal(err)
-		}
+		wg.Add(1)
+		go func(i int) {
+			var p pserver.Parameter
+			p.Name = "p_" + strconv.Itoa(i)
+			p.ElementType = pserver.Float32
+			p.Content = make([]byte, (i+1)*100)
+			err := c.InitParam(pserver.ParameterWithConfig{Param: p, Config: config})
+			if err != nil {
+				t.Fatal(err)
+			}
+			wg.Done()
+		}(i)
 	}
+	wg.Wait()
 
 	err = c.FinishInitParams()
 	if err != nil {
@@ -136,9 +145,31 @@ func testClient(t *testing.T, c *client.Client) {
 		grads = append(grads, g)
 	}
 
-	err = c.SendGrads(grads)
-	if err != nil {
-		t.Fatal(err)
+	const paramPerGroup = 10
+	const numGroups = numParameter / paramPerGroup
+
+	// shuffle send grads order
+	for i := range grads {
+		j := rand.Intn(i + 1)
+		grads[i], grads[j] = grads[j], grads[i]
+	}
+
+	for i := 0; i < numGroups; i++ {
+		var gs []pserver.Gradient
+		if i == numGroups-1 {
+			gs = grads[i*paramPerGroup:]
+		} else {
+			gs = grads[i*paramPerGroup : (i+1)*paramPerGroup]
+		}
+
+		wg.Add(1)
+		go func(gs []pserver.Gradient) {
+			err = c.SendGrads(gs)
+			if err != nil {
+				t.Fatal(err)
+			}
+			wg.Done()
+		}(gs)
 	}
 
 	names := make([]string, numParameter)
@@ -146,20 +177,35 @@ func testClient(t *testing.T, c *client.Client) {
 		names[i] = "p_" + strconv.Itoa(i)
 	}
 
-	params, err := c.GetParams(names)
-	if err != nil {
-		t.Fatal(err)
-	}
+	for i := 0; i < numGroups; i++ {
+		var ns []string
+		if i == numGroups-1 {
+			ns = names[i*paramPerGroup:]
+		} else {
+			ns = names[i*paramPerGroup : (i+1)*paramPerGroup]
+		}
 
-	if len(names) != len(params) {
-		t.Fatalf("parameter size not match, need: %d, have: %d", len(names), len(params))
-	}
+		wg.Add(1)
+		go func(ns []string) {
+			params, err := c.GetParams(ns)
+			if err != nil {
+				t.Fatal(err)
+			}
 
-	for i := range params {
-		if names[i] != params[i].Name {
-			t.Fatalf("order of returned parameter does not required: parameter name: %s, required name: %s", names[i], params[i].Name)
-		}
+			if len(ns) != len(params) {
+				t.Fatalf("parameter size not match, need: %d, have: %d", len(names), len(params))
+			}
+
+			for i := range params {
+				if ns[i] != params[i].Name {
+					t.Fatalf("order of returned parameter does not required: parameter name: %s, required name: %s", ns[i], params[i].Name)
+				}
+			}
+			wg.Done()
+		}(ns)
 	}
+
+	wg.Wait()
 }
 
 func TestNativeClient(t *testing.T) {